// clang test-file-option.c && ./a.out
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/stat.h>

int
main(int argc, char *argv[])
{
    struct stat sbuf;
    int ret = 2;
    ret = stat("a.out", &sbuf);
    if (ret == -1) {
        perror("stat error:");
        exit(1);
    }
    printf("len=%ld\n", sbuf.st_size);
    return 0;
}